1 /*
2  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by John Birrell.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $DragonFly: src/lib/libthread_xu/thread/thr_join.c,v 1.7 2006/04/06 13:03:09 davidxu Exp $
33  */
34 
35 #include "namespace.h"
36 #include <machine/tls.h>
37 
38 #include <errno.h>
39 #include <pthread.h>
40 #include "un-namespace.h"
41 
42 #include "thr_private.h"
43 
44 int _pthread_timedjoin_np(pthread_t pthread, void **thread_return,
45 	const struct timespec *abstime);
46 
47 static int join_common(pthread_t, void **, const struct timespec *);
48 
49 static void backout_join(void *arg)
50 {
51 	struct pthread *curthread = tls_get_curthread();
52 	struct pthread *pthread = (struct pthread *)arg;
53 
54 	THREAD_LIST_LOCK(curthread);
55 	pthread->joiner = NULL;
56 	THREAD_LIST_UNLOCK(curthread);
57 }
58 
59 int
60 _pthread_join(pthread_t pthread, void **thread_return)
61 {
62 	return (join_common(pthread, thread_return, NULL));
63 }
64 
65 int
66 _pthread_timedjoin_np(pthread_t pthread, void **thread_return,
67 	const struct timespec *abstime)
68 {
69 	if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
70 	    abstime->tv_nsec >= 1000000000)
71 		return (EINVAL);
72 
73 	return (join_common(pthread, thread_return, abstime));
74 }
75 
76 static int
77 join_common(pthread_t pthread, void **thread_return,
78 	const struct timespec *abstime)
79 {
80 	struct pthread *curthread = tls_get_curthread();
81 	struct timespec ts, ts2, *tsp;
82 	void *tmp;
83 	long state;
84 	int oldcancel;
85 	int ret = 0;
86 
87 	if (pthread == NULL)
88 		return (EINVAL);
89 
90 	if (pthread == curthread)
91 		return (EDEADLK);
92 
93 	THREAD_LIST_LOCK(curthread);
94 	if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) {
95 		ret = ESRCH;
96 	} else if ((pthread->tlflags & TLFLAGS_DETACHED) != 0) {
97 		ret = ESRCH;
98 	} else if (pthread->joiner != NULL) {
99 		/* Multiple joiners are not supported. */
100 		ret = ENOTSUP;
101 	}
102 	if (ret) {
103 		THREAD_LIST_UNLOCK(curthread);
104 		return (ret);
105 	}
106 	/* Set the running thread to be the joiner: */
107 	pthread->joiner = curthread;
108 
109 	THREAD_LIST_UNLOCK(curthread);
110 
111 	THR_CLEANUP_PUSH(curthread, backout_join, pthread);
112 	oldcancel = _thr_cancel_enter(curthread);
113 
114 	while ((state = pthread->state) != PS_DEAD) {
115 		if (abstime != NULL) {
116 			clock_gettime(CLOCK_REALTIME, &ts);
117 			TIMESPEC_SUB(&ts2, abstime, &ts);
118 			if (ts2.tv_sec < 0) {
119 				ret = ETIMEDOUT;
120 				break;
121 			}
122 			tsp = &ts2;
123 		} else
124 			tsp = NULL;
125 		ret = _thr_umtx_wait(&pthread->state, state, tsp,
126 			 CLOCK_REALTIME);
127 		if (ret == ETIMEDOUT)
128 			break;
129 	}
130 
131 	_thr_cancel_leave(curthread, oldcancel);
132 	THR_CLEANUP_POP(curthread, 0);
133 
134 	if (ret == ETIMEDOUT) {
135 		THREAD_LIST_LOCK(curthread);
136 		pthread->joiner = NULL;
137 		THREAD_LIST_UNLOCK(curthread);
138 	} else {
139 		ret = 0;
140 		tmp = pthread->ret;
141 		THREAD_LIST_LOCK(curthread);
142 		pthread->tlflags |= TLFLAGS_DETACHED;
143 		pthread->joiner = NULL;
144 		THR_GCLIST_ADD(pthread);
145 		THREAD_LIST_UNLOCK(curthread);
146 
147 		if (thread_return != NULL)
148 			*thread_return = tmp;
149 	}
150 	return (ret);
151 }
152 
153 __strong_reference(_pthread_join, pthread_join);
154 __strong_reference(_pthread_timedjoin_np, pthread_timedjoin_np);
155 
156